1. Field of the Invention
The present invention relates to an improvement of a graphic data processing apparatus using a computer generally called a CAD (Computer Aided Design) system or a CAD/CAM (Computer Aided Design/Computer Aided Manufacturing) system.
2. Description of the Prior Art
FIG. 1 is an illustration showing an example of a display screen of a conventional CAD/CAM system. Referring to FIG. 1, operation for displaying graphic data such as a graphic form, characters or symbols on the display screen by using the conventional CAD/CAM system will be described.
A menu area 12 is provided for example in a lower portion of the display screen 10. Ten commands at maximum for example can be displayed at a time in the menu area 12. A user selects a desired command, if any, out of the commands displayed in the menu area 12. If there is not any desired command among the displayed commands, the user advances the display in the menu area 12 to search for a desired command in a manner of turning over display pages whereby the desired command is selected.
More specifically stated, in order to draw a circle for example, operation is to be performed in the following manner. First of all, the following commands are displayed in the menu are 12:
xe2x80x9c{circle around (1)} layer, {circle around (2)} change of frames, {circle around (3)} setting of a reference, {circle around (4)} cancellation of the reference, {circle around (5)} zoom, {circle around (6)} drawing, {circle around (7)} next item, {circle around (8)} menuxe2x80x9d
The user designates the command xe2x80x9c{circle around (6)} drawingxe2x80x9d by using a pointing device such as a mouse, a light pen or a cursor. Then, the following commands appear in the menu area:
xe2x80x9c{circle around (1)} line segment, {circle around (2)} continuous line, {circle around (3)} auxiliary line, {circle around (4)} circle, {circle around (5)} cross, {circle around (6)} arc, {circle around (7)} sector, {circle around (8)} spline, {circle around (9)} next item, {circle around (10)} risexe2x80x9d
appear in the menu area 12. Thus, if the command xe2x80x9c{circle around (4)} circlexe2x80x9d is designated by the pointing device, a command mode for drawing a circle is set, whereby a program for drawing a circle is read out.
If the user wants to draw xe2x80x9ccharactersxe2x80x9d, he designates the command xe2x80x9c{circle around (9)} next itemxe2x80x9d appearing in the menu area 12 and changes display pages repeatedly until a desired command, namely, a command xe2x80x9ccharactersxe2x80x9d appears.
After having set the desired command mode, for example, the command xe2x80x9ccirclexe2x80x9d, the user designates, by using the pointing device, a place where a circle is to be drawn on a graphic display area 14 of the display screen 10. In the case of drawing a xe2x80x9ccirclexe2x80x9d, the user designates for example a center point (center coordinates) and a radius by using the pointing device. As a result, the circle is drawn. Attributes of the circle thus drawn, namely, data as to whether the circle is represented by a solid line, a dotted line or a chained line, and data as to the color of the line, the thickness of the line etc. are displayed in an attribute display area 16. It is also possible to change attributes of the thus drawn circle.
The number of commands for data processing increases, as performance of a CAD/CAM system becomes high. Accordingly, in the case of command display using the menu area 12 where only about less than ten commands can be displayed at a time, tens of pages for display of commands are required. As a result, it takes much time and labor to search for a desired command.
If the user knows which page contains which commands, the commands can be searched relatively smoothly. However, in order to do so, the user needs to have much skill in use of the apparatus.
On the other hand, there is a system for inputting commands from a tablet 18 (as shown in FIG. 1) instead of the menu area 12. However, in this system for inputting commands by the tablet 18, it is not easy to search for a desired command out of all of the commands displayed on the tablet 18, for example, more than 100 commands, which involves disadvantages that much time is required for selection of desired commands.
In addition, in either system using the menu 12 or the tablet 18, a content of each command is often expressed by an extremely short abbreviation. For example, a command indicating xe2x80x9cdraw a straight linexe2x80x9d is expressed as xe2x80x9cLNxe2x80x9d and a command indicating xe2x80x9cdraw a circlexe2x80x9d is expressed as xe2x80x9cCRxe2x80x9d. Therefore, if such a command display method using abbreviations is adopted, training for having knowledge of contents of the commands is also required.
The present invention has been accomplished to solve the above described problems involved in a conventional apparatus.
Therefore, it is an object of the present invention to provide a graphic data processing apparatus and method which allow easy, quick and exact designation of commands at the time of selecting commands to display a graphic form, characters, symbols, or the like on a display screen.
It is another object of the present invention to provide a graphic data processing apparatus which can be easily operated.
In a graphic data processing apparatus of the present invention, an arbitrary displayed portion out of already displayed graphic data such as a graphic form, characters or symbols is designated by display designating means and the data concerning the designated displayed portion is detected by storage means so that program is selected based on the detected content.
When a desired portion of the already displayed graphic form, characters or symbols is designated, a command for displaying the designated graphic form or the like is selected so that program corresponding thereto is read out. Consequently, it is not needed to select a desired command out of a large number of commands, and thus selection of commands can be effected rapidly and correctly by using the already displayed graphic form or the like.
According to another aspect of the present invention, it is possible to select a drawing program for drawing a basic display element constituting a graphic form by designating a part of the graphic form and it is also possible to select a drawing program for drawing the graphic form per se, that is, a composite display element. When a program for drawing a basic display element is selected, the same graphic form as the basic display element can be drawn on a display. When a program for drawing a composite display element is selected, the same graphic form as the composite display element can be drawn on the display.
According to a further aspect of the invention, a plurality of drawing programs related with display elements constituting a graphic form are displayed in a menu form by designation of a part of the graphic form. By selection of a menu, it is possible to draw a desired graphic form using one drawing program.
These objects and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.